<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>下拉菜单</title>
    <style>
        .dropdown {
            position: relative;
        }
        .dropdown-content {
            display: none;
            position: absolute;
            min-width: 160px;
            padding: 12px 16px;
        }
        .dropdown:hover .dropdown-content{
            display: block;
        }
    </style>
</head>
<body>
    <div class="dropdown">
        <span>鼠标移动到我这!</span>
        <div class="dropdown-content">
            <p>菜鸟教程</p>
            <p>www.runoob.com</p>
        </div>
    </div>
</body>
</html>